Enriched rice or enriched wheat

ABSTRACT

The present invention relates to enriched rice or barley characterized in that rice grains or barley grains are coated with an emulsifying agent-coated iron salt composition and vitamins, and further coated with a mixture of a hydrogenated oil and a polyglycerol fatty acid ester. The present invention also relates to enriched rice or enriched barley characterized in that rice grains or barley grains are coated with a mixture comprising an iron salt, a hydrogenated oil and a polyglycerol fatty acid ester. Further, the present invention relates to enriched rice or enriched barley characterized in that rice grains or barley grains are coated with a mixture comprising an emulsifying agent-coated iron salt composition, vitamins, a hydrogenated oil, and a polyglycerol fatty acid ester.

TECHNICAL FIELD

The present invention relates to iron- and vitamin-enriched oriron-enriched, rice or barley.

BACKGROUND ART

In a diet in Japan where rice has been a principal food, recently, wheatproducts such as bread have come to be taken as principal foods otherthan rice, and instant processed foods have come to be widely utilized.As a result, the diet has become nutritionally imbalanced, and theinfluence of the imbalance on human health has become a social concern.As a method of supplementing the imbalance as described above, interalia, enriched polished rice or the like in which the surface of rice isenriched with vitamin B₁ and other water-soluble vitamins, fat-solublevitamins and other nutrients which are likely to be deficient are madecommercially available, and widely taken as food.

The enrichment as described above is made and provided, for example, bya method comprising macerating raw polished rice or raw polished barleyin an acidic solution in which enrichment nutrients are dissolved,steam-boiling the rice or barley for a short time to include thenutrients, and subjecting the cooked rice or barley to hot-air drying; amethod comprising emulsifying water-insoluble, fat-soluble nutrients,mixing water-soluble vitamins and mineral nutrients such as calcium andiron in proper amounts desired to be enriched to give an aqueoussolution, or adding the water-soluble components to the emulsion,coating the surface of polished rice or the like with those nutrientsby, for example, utilizing a fluidized granulator, a centrifugalfluidized coating granulator or the like, and drying the surface.However, a problem that a considerable amount of those nutrients adheredfor enrichment is run off and lost in washing rice or the like withwater before cooking has not been unavoidable. In order to prevent theproblem, in a case other than the processing as “musenmai” (wash-freerice, rice which does not need washing with water before cooking), it isdesired that the adhered nutrients are fixed to rice or the like so asnot to easily migrate to an aqueous phase while washing with water.However, an effective coating method for practical use has not yet beenfound at present. In addition, since a method of coating with zein orshellac necessitates large-scaled manufacturing facilities, thosemethods have not so far been adopted industrially.

A method of coating with an emulsion of a fat or oil and a wax describedin JP-B-Hei-5-30426 (JP-A-Showa-59-130157) has a problem of lowering inflavor because of the use of the wax.

In addition, the method using ethanol described in JP-A-Hei-8-56593 hassome problems, for example, that only those soluble in ethanol can beused as coating agents, and there is a risk that ethanol used in thecoating may ignite fire.

Furthermore, there is a problem that lowering in activities of vitaminstakes place early in the presence of an iron salt, so that it isdifficult to stably enrich with iron and vitamins at the same time.Therefore, the countermeasure for this problem has not so far been drawnup.

DISCLOSURE OF INVENTION

An object of the present invention is to provide stable enriched rice orenriched barley capable of being manufactured industrially safely, inwhich run-off of iron or the like adhered to the surface of rice grainsor barley grains when washing rice in an ordinary manner (washing ricewith water), and lowering in the activity of the vitamins caused by ironwhen iron and vitamins are adhered at the same time are suppressed.

Another object of the present invention is to provide stable enrichedrice or enriched barley, which is industrially safe, and capable ofbeing manufactured easily in a single coating step, in which run-off ofiron and the like adhered to the surfaces of rice grains or barleygrains is reduced when washing rice in an ordinary manner (washing withwater).

In a first embodiment, the present invention provides stable enrichedrice or enriched barley capable of being manufactured industriallysafely, in which rice grains or barley grains are coated with anemulsifying agent-coated iron salt composition and vitamins, and furthercoated with a mixture of a hydrogenated oil and a polyglycerol fattyacid ester, whereby run-off of iron and vitamins adhered to the surfaceof the rice grains or barley grains and lowering of activities ofvitamins caused by iron are suppressed.

In a second embodiment, the present invention provides stable enrichedrice or enriched barley, which is industrially safe, and capable ofbeing manufactured easily in a single coating step, in which rice grainsor barley grains are coated with a mixture comprising an iron salt, ahydrogenated oil and a polyglycerol fatty acid ester, whereby run-off ofiron when the rice is washed is suppressed.

In a third embodiment, the present invention provides stable enrichedrice or enriched barley, which is industrially safe, and capable ofbeing manufactured easily in a single coating step, in which rice grainsor barley grains are coated with a mixture comprising an emulsifyingagent-coated iron salt composition, vitamins, a hydrogenated oil and apolyglycerol fatty acid ester, whereby run-off of iron and vitaminsadhered to the surface of rice grains or barley grains when rice iswashed and lowering of activities of vitamins by iron are suppressed.

BEST MODE FOR CARRYING OUT THE INVENTION

First, the first embodiment will be explained.

The rice in this embodiment is not limited by its kind, and may be anyof nonglutinous rice, glutinous rice, upland rice, indica type rice,javanica type rice and the like. The rice in this embodiment is notlimited by the degree of polishing, and can be any of polished rice,polished rice with embryo, 70% bran-polished rice (nanabuzukimai), 50%bran-polished rice (gobuzukimai), unpolished rice and the like.

The barley in this embodiment is not limited by its kind, and may be anyof barley, bread wheat, club wheat, durum wheat, adlay, oats, rye andthe like. The barley in this embodiment is not limited by the degree ofpolishing or the shape, and may be any of pressed barley, bisectedmilled barley, rice grain-like barley and the like.

The iron salt in this embodiment is not particularly limited, and refersto ferric pyrophosphate, ferric citrate, ferrous sodium citrate, ferroussulfate, ferric gluconate, iron lactate, ferric hydroxide, ferricchloride, ferrous fumarate, iron sesquioxide, iron threonine or thelike. These iron salts can be used alone or in combination of pluralkinds. From the viewpoint of suppressing run-off of iron when washingrice, an iron salt insoluble in water, such as ferric pyrophosphate,ferrous fumarate, or iron threonine is preferable, and also inconsideration of color tone and flavor, ferric pyrophosphate is mostpreferable. Here, the term insoluble refers to those that are “verydifficult to dissolve” (the amount of water necessary for dissolving 1 gof a solute is 1,000 ml or more and less than 10,000 ml) or “hardlysoluble” (the amount of water necessary for dissolving 1 g of a soluteis 10,000 ml or more) according to the test method of the JapaneseStandards of Food Additives 7th Ed., General Provision 29, and the termpreferably corresponds to those that are “hardly soluble.”

The emulsifying agent-coated iron salt composition in this embodiment isnot particularly limited, as long as the iron salt is coated with anemulsifying agent. The emulsifying agent usable for coating is notparticularly limited, and a general emulsifying agent for food, forexample, a sucrose fatty acid ester, a glycerol fatty acid ester, apropylene glycol fatty acid ester, a sorbitan fatty acid ester, anenzymatically decomposed lecithin or the like can be used alone or incombination of plural kinds. It is desired to use an enzymaticallydecomposed lecithin having high coating effect.

The enzymatically decomposed lecithin in this embodiment is notparticularly limited, as long as it is a product obtained by hydrolyzinglecithin with a phospholipase or the like. As for the raw materiallecithin, any of a plant-derived lecithin such as soybean and ananimal-derived lecithin such as an egg yolk can be used. As for thephospholipase, any of phospholipases can be used as long as thephospholipase possesses a phospholipase A and/or D activity, regardlessof the origin, such as those originated from an animal such as pigpancreas, those originated from a plant such as cabbage, and thoseoriginated from a microbe such as mold. The phospholipase A, which is anenzyme hydrolyzing a fatty acid ester on 1- or 2-position of diacylglycerophospholipid, is preferable, and phospholipase A₂ hydrolyzing2-position of diacyl glycerophospholipid is more preferable.

When coating the iron salt, although a satisfactory effect is obtainedwith single use of the enzymatically decomposed lecithin, it ispreferable to use the enzymatically decomposed lecithin together withother surfactant components such as an emulsifying agent for foods, suchas a sucrose fatty acid ester, a glycerol fatty acid ester, a propyleneglycol fatty acid ester, or a sorbitan fatty acid ester, a saponincompound originated from quillaia or Yucca foam is more preferablebecause the dispersibility of an iron salt in a coating liquid used forcoating rice grains or barley grains is improved, whereby the iron saltcan be coated more homogeneously. Especially, the nonionic detergent ismore preferable because systemic absorbability of the iron salt is alsoenhanced.

The above-mentioned nonionic detergent includes, but not particularlylimited to, for example, a polyglycerol fatty acid ester, a sucrosefatty acid ester, a glycerol fatty acid ester, a propylene glycol fattyacid ester, a sorbitan fatty acid ester, a pentaerythritol fatty acidester, a sorbitol fatty acid ester and the like. Among them, thepolyglycerol fatty acid ester is preferable. The polyglycerol fatty acidester as used herein is an ester formed between a polyglycerol and afatty acid, and the average degree of polymerization, the kind of thefatty acid and the degree of esterification of the polyglycerolconstituting the ester are not particularly limited. The polyglycerolconstituting the polyglycerol fatty acid ester has an average degree ofpolymerization of preferably 3 or more, more preferably from 3 to 11.The fatty acid constituting the polyglycerol fatty acid ester haspreferably from 6 to 22 carbon atoms, more preferably from 8 to 18carbon atoms, most preferably from 12 to 14 carbon atoms. The fatty acidcan be any of those saturated or unsaturated, or those which havehydroxyl group on linear or branched chain.

Moreover, the methods for coating an iron salt with an emulsifying agentincludes, but not particularly limited to, for example, a methodcomprising carrying out neutralization and salt-formation reaction in asolution in which an emulsifying agent is dissolved to give aprecipitate, subjecting the mixture to a liquid-solid separation; amethod comprising mixing an iron salt and a solution prepared bydissolving an emulsifying agent in a solvent capable of dissolving theemulsifying agent such as water, and removing the solvent by means ofspray-drying, lyophilization or the like; a method comprising previouslyheating an emulsifying agent to melt, mixing an iron salt therewith, andthereafter cooling the mixture to solidify. In addition, when theemulsifying agent is in the form of a liquid at room temperature, amethod comprising mixing an iron salt homogeneously as it is can be alsoemployed.

Among them, the method utilizing neutralization and salt-formationdescribed in WO 98/14072 is most preferable because the particle size ofthe emulsifying agent-coated iron salt composition can be controlled tobe small, and more homogeneous coating can be achieved when rice grainsor barley grains are coated.

For example, in the case of an emulsifying agent-coated ferricpyrophosphate composition, the emulsifying agent-coated ferricpyrophosphate composition can be obtained in a solid phase portion byadding an iron solution prepared by dissolving ferric chloridehexahydrate and enzymatically decomposed lecithin gradually to apyrophosphate solution prepared by dissolving tetrasodium pyrophosphatedecahydrate and pentaglycerol monomyristate with stirring, forming asalt by neutralization reaction, and thereafter subjecting the mixtureto a liquid-solid separation.

The emulsifying agent-coated iron salt composition in this embodimenthas an average particle size as determined by laser diffraction particlesize distribution of preferably 2 μm or less, more preferably from 0.05to 2 μm. Methods for obtaining an average particle size of this rangeare not particularly limited. For example, in the case of theabove-mentioned method utilizing neutralization and salt-formation, themethod includes a method comprising adjusting mixing rates of both thesolutions, thereby adjusting the salt-formation reaction rate; in thecase of the method in which other powder form iron salt is used as a rawmaterial, the method includes a method comprising pulverizing the ironsalt with a pulverizer such as Cobol Mill in an emulsifying agentsolution. In the case where those having particle sizes not exceeding 2μm are utilized, excellent dispersibility of the iron salt in a coatingliquid is obtained when the rice grains or barley grains are coated, sothat even more homogeneous coating is achieved when rice grains orbarley grains are coated.

The iron content in solid content of the emulsifying agent-coated ironsalt composition is preferably from 1 to 15% by weight, more preferablyfrom 5 to 10% by weight.

The vitamins in this embodiment are not particularly limited as long asthese are generally referred to as vitamins. The vitamins includevitamin A, vitamin B₁, vitamin B₂, vitamin B₆, vitamin B₁₂, vitamin C,vitamin D, vitamin E, niacin (nicotinic acid), pantothenic acid, folicacid and the like.

As to the iron salt and vitamins, the kinds of nutrients and each of theamounts can be properly selectively adhered and enriched depending uponthe desired enrichment. For example, vitamin B₁ can be added inreference to the standard amount of Japanese special nutritive foods soas to have a concentration of from 100 to 150 mg per 100 g of rice. Inaddition, vitamin B₁ can be enriched so as to supplement the deficiencyin reference to the results of the national nutrition survey in Japan.Alternatively, the nutritional level of rice or the like can be enhancedin agreement to that of the original unpolished rice or the like.

Also, one or more kinds of essential amino acids such as lysine,threonine, tryptophan, minerals other than iron such as calcium andmagnesium, compounds contributing to human wellness such as α-linolenicacid, EPA, DHA, evening primrose oil, octacosanol, casein phosphopeptide(CPP), casein calcium peptide (CCP), dietary fiber, oligosaccharide, andother useful compounds approved as food additives can be added at thesame time.

The hydrogenated oil in this embodiment is not particularly limited aslong as the hydrogenated oil does not melt at an ordinary temperature.Usually, the hydrogenated oil is an fat or oil having a melting point of40° C. or higher, and includes vegetable hydrogenated oils such assoybean hydrogenated oil, cottonseed hydrogenated oil, rapeseedhydrogenated oil, rice hydrogenated oil, and Indian corn hydrogenatedoil; animal fats and oils such as beef tallow and lard; and animalhydrogenated oils obtained by hydrogenation of animal fats and oils.From the viewpoint of influence on taste or the like, the vegetablehydrogenated oil is preferable.

The polyglycerol fatty acid ester used together with the hydrogenatedoil in this embodiment is an ester formed between a polyglycerol and afatty acid, and the average degree of polymerization of the polyglycerolconstituting this ester, the kinds of the fatty acid, and theesterification ratio are not particularly limited. The polyglycerolconstituting the polyglycerol fatty acid ester has an average degree ofpolymerization of preferably 3 or more, more preferably from 3 to 11.The fatty acid constituting the polyglycerol fatty acid ester ispreferably a fatty acid having hydroxyl groups on saturated orunsaturated straight or branched chain having 8 to 20 carbon atoms orcondensed ricinoleic acid.

Specifically, one or more kinds selected from hexaglycerol hexastearate,hexaglycerol octastearate, hexaglycerol condensed ricinoleate,pentaglycerol condensed ricinoleate are preferable, and combined use ofone or more kinds selected from hexaglycerol hexastearate andhexaglycerol octastearate and one or more kinds selected fromhexaglycerol condensed ricinoleate and pentaglycerol condensedricinoleate are more preferable.

The amount of the polyglycerol fatty acid ester added to thehydrogenated oil is not particularly limited. The amount of thepolyglycerol fatty acid ester is preferably from 0.5 to 20 parts byweight, more preferably 0.5 to 10 parts by weight, based on 100 parts byweight of the hydrogenated oil. It is preferable that the amount of thepolyglycerol fatty acid ester is within this range, because homogeneouscoating can be achieved on the surface of rice or barley, and thecoating is less likely to be peeled off, so that enriched iron andvitamins are less likely to run off.

In the method for producing the enriched rice or enriched barley of thisembodiment, rice grains or barley grains can be first coated with anemulsifying agent-coated iron salt composition and vitamins, andthereafter further coated with a mixture of the hydrogenated oil and apolyglycerol fatty acid ester.

In this embodiment, the method of coating rice grains or barley grainswith an emulsifying agent-coated iron salt composition and vitamins isnot particularly limited, as long as the rice grains or barley grainscan be homogeneously coated, and a conventionally employed method can beutilized except that the emulsifying agent-coated iron salt compositionis used as an iron salt. The method includes, for example, a methodcomprising placing rice or barley in a rotating coating pan, andspraying a solution prepared by dispersing the emulsifying agent-coatediron salt composition and vitamins in water or the like onto the rice orbarley to coat; a method comprising carrying out the same procedures ina fluidized granulator with supplying hot air; a method comprisingallowing rice or barley to swell in a solution prepared by dispersingthe emulsifying agent-coated iron salt composition and vitamins in wateror the like to absorb the iron salt and the vitamins in the rice orbarley, and drying the product. Especially, a method utilizingspray-coating having a small degree of pyrolysis of vitamins due to heatis preferable, because an even more homogeneous coating can be provided.

It is preferable to add a polyglycerol fatty acid ester to the solutionfor dispersing the emulsifying agent-coated iron salt composition andvitamins because the dispersibility of the emulsifying agent-coated ironsalt composition and fat-soluble vitamins becomes excellent. In thiscase, the polyglycerol fatty acid ester can be used for the purpose ofemulsifying fat-soluble vitamins and the like.

Here, when further enriched with nutrients other than iron and vitamins,rice or barley can be coated with a mixture of further nutrientstogether with the emulsifying agent-coated iron salt composition andvitamins in this coating solution.

In this embodiment, the method of coating iron- and vitamin-coated ricegrains or barley grains with a mixture of a hydrogenated oil and apolyglycerol fatty acid ester is not particularly limited, andconventionally employed methods except that a mixture of a hydrogenatedoil and a polyglycerol fatty acid ester can be utilized. The methodincludes, for example, a method comprising placing iron- andvitamin-coated rice or barley in a coating pan, and spraying ahydrogenated oil in which a polyglycerol fatty acid ester is dissolvedat an ordinary temperature or with blowing hot air therein to coat; anda method comprising carrying out the same procedures in a fluidizedgranulator. Among them, a method utilizing spray-coating which iscapable of even more homogeneous coating is preferable.

A pigment such as vitamin B₂, β-carotene, or crocin pigment may be addedto this coating solution for the purpose of coloring the final enrichedrice or enriched barley.

The preferred composition of the enriched rice or enriched barley ofthis embodiment is 5 to 10 parts by weight of the emulsifyingagent-coated iron salt composition, 0.1 to 2 parts by weight ofvitamins, 1 to 8 parts by weight of the hydrogenated oil and 0.1 to 5parts by weight of the polyglycerol fatty acid ester based on 100 partsby weight of rice grains or barley grains.

Next, the second embodiment will be explained.

In this embodiment, rice, barley, and an iron salt refers to the sameones as those in the first embodiment. However, the iron salt used inthis embodiment is an iron salt itself without being coated with anemulsifying agent. The average particle size of the iron salt is notparticularly limited, and the average particle diameter as determined bylaser diffraction type particle size distribution is preferably 2 μm orless, more preferably 1 μm or less, most preferably 0.5 μm or less. Thelower limit of the average particle diameter is about 0.05 μm. When theaverage particle size is 2 μm or less, more homogeneous coating can beaccomplished when rice grains or barley grains are coated. A method forobtaining an iron salt of this average particle size include a methodaccording to neutralization and salt-formation (WO 98/14072), a methodof pulverizing an iron salt with a dry-type pulverizer such as a jetmill, or a wet-type pulverizer such as Cobol Mill and Dyno-Mill. Amethod of pulverizing an iron salt with a wet-type pulverizer in apolyglycerol fatty acid ester and a hydrogenated oil is preferable,because pulverization and homogenous mixing-and-dispersion can beaccomplished at the same time.

In this embodiment, the polyglycerol fatty acid ester refers to the sameone as that used together with the hydrogenated oil in the firstembodiment. The polyglycerol fatty acid ester suitable for thisembodiment has an HLB calculated from a ratio of the molecular weightsof hydrophilic groups and lipophilic groups of preferably 5 or less,more preferably 4 or less.

In addition, in this embodiment, an emulsifying agent for foods otherthan the polyglycerol fatty acid ester can be used together. Theemulsifying agent for foods includes, for example, a sucrose fatty acidester, a glycerol fatty acid ester, a propylene glycol fatty acid ester,a sorbitan fatty acid ester, lecithin, enzymatically decomposedlecithin, and the like.

In this embodiment, the hydrogenated oil includes those exemplified inthe first embodiment. The hydrogenated oil suitable for this embodimentis usually an oil having a melting point of 30° C. or higher, and an oilhaving a melting point of 35° C. or higher is preferable.

The amount of the iron salt is not particularly limited, and can beadjusted depending on the kinds of the iron salt according to thedesired ratio of enrichment. The iron salt can be formulated in anamount of usually from 1 to 100 parts by weight, based on 100 parts byweight of the hydrogenated oil. The lower limit of the amount of theiron salt is preferably 10 parts by weight, more preferably 25 parts byweight based on 100 parts by weight of the hydrogenated oil. When theamount of the iron salt is 1 part by weight or more, it is practicalbecause a large amount of the mixture would not be necessary forenrichment with iron. The upper limit of the amount of the iron salt ispreferably 90 parts by weight, more preferably 75 parts by weight basedon 100 parts by weight of the hydrogenated oil. When the amount of theiron salt is 100 parts by weight or less, the coating of the iron saltwith the hydrogenated oil is satisfactory, so that the iron salt will beprevented from being run-off while washing rice with water.

The amount of the polyglycerol fatty acid ester is not particularlylimited, and the polyglycerol fatty acid ester can be formulated in anamount of from 0.1 to 100 parts by weight based on 100 parts by weightof the hydrogenated oil. The lower limit of the amount of thepolyglycerol fatty acid ester is preferably 1 part by weight, morepreferably 5 parts by weight based on 100 parts by weight of thehydrogenated oil. When the amount of the polyglycerol fatty acid esteris 0.1 parts by weight or more, it is practical because the iron saltcan be sufficiently dispersed. The upper limit of the amount of thepolyglycerol fatty acid ester is preferably 50 parts by weight, morepreferably 20 parts by weight based on 100 parts by weight of thehydrogenated oil. When the amount of the polyglycerol fatty acid esteris 100 parts by weight or less, run-off of the components incorporatedby emulsification phase inversion is less likely to take place whilewashing rice with water.

In this embodiment, the material for enrichment of rice or barley is notlimited to iron alone, and other materials described in the firstembodiment which would not cause lowering of the activity by iron can beused for enrichment.

The amount of these materials is such that the kinds of nutrients andthe amount of each nutrient are selectively adhered for enrichmentaccording to desired enrichment. These materials can be mixed with thepolyglycerol fatty acid ester and the hydrogenated oil at the same timeas the iron salt, and the rice grains or barley grains may be coatedwith the mixture.

Among them, an oil-soluble material may be dissolved in a hydrogenatedoil. As to an oil-insoluble material, it is desired to pulverize thematerial in the same manner as the iron salt so as to have an averageparticle size as determined by laser diffraction particle sizedistribution of preferably 2 μm or less, more preferably 1 μm or less,most preferably 0.5 μm or less, because more homogeneous coating can beaccomplished when rice grains or barley grains are coated. As in thecase with the above-mentioned iron salt, this pulverization may bepreferably carried out by a method of pulverization with a wet-typepulverizer, and pulverization can be carried out with a pulverizer atthe same time as the iron salt.

In the method for producing the enriched rice or barley of thisembodiment, a mixture comprising an iron salt, a hydrogenated oil and apolyglycerol fatty acid ester can coat rice grains or barley grains. Amixture comprising an iron salt, a hydrogenated oil and a polyglycerolfatty acid ester can be then used directly, or used as an emulsionprepared by emulsifying the mixture in water. Direct use is preferablesince a step such as drying is not required.

In this embodiment, the method for coating rice grains or barley grainswith a mixture comprising an iron salt, a hydrogenated oil and apolyglycerol fatty acid ester is not particularly limited as long ashomogeneous coating can be accomplished on rice grains or barley grains.The method includes, for example, a method comprising placing rice orbarley in a rotating coating pan, and spray-coating a mixture comprisingan iron salt, a hydrogenated oil and a polyglycerol fatty acid ester tothe rice or barley, with blowing hot air thereinto, a method comprisingcarrying out the same procedures in a fluidized granulator. Among them,a method according to spray-coating is preferable because morehomogeneous coating can be achieved.

As in the case of the first embodiment, a pigment such as vitamin B₂,β-carotene or crocin pigment can be added to this coating solution forthe purpose of coloring the finished enriched rice or enriched barley.

Next, the third embodiment will be explained.

In this embodiment, rice, barley, the emulsifying agent-coated iron saltcomposition, the vitamins and the hydrogenated oil are the same ones asthose in the first embodiment. The polyglycerol fatty acid ester refersto those used together with the hydrogenated oil in the firstembodiment. The quantitative relationship of each of the components usedis the same as that in the first embodiment.

In the method for producing enriched rice or barley of this embodiment,the rice grains or barley grains can be coated with a mixture comprisingan emulsifying agent-coated iron salt composition, vitamins, ahydrogenated oil and a polyglycerol fatty acid ester in the same manneras in the second embodiment.

The enriched rice or barley of the present invention can be used byadding to and mixing with ordinary (i.e. untreated) rice or barley, orthe enriched rice or barley can be used alone, when preparation ofcooked rice and the like. The ratio of the amount of the enriched riceor barley to ordinary rice or barley is not particularly limited, andthe ratio can be arbitrarily set depending upon the degree of enrichmentof nutrients for the enriched rice or barley, or the amount intended forenrichment of nutrients to cooked rice or the like. In the case wherethe enriched rice or barley is added to and mixed with ordinary rice orbarley, the enriched rice or barley of the present invention can beadded usually in an amount of from 0.01 to 10 parts by weight,preferably from 0.1 to 2 parts by weight based on 100 parts by weight ofthe untreated rice or barley.

Here, the cooked rice and the like as used herein refers to thoseprepared by cooking rice and/or barley, such as plain cooked rice,glutinous rice boiled together with azuki beans or cowpea, a rice gruel,a porridge of rice boiled together with vegetables, seafoods and thelike, pilaf, fried rice, doria, risotto, rice boiled with barley, andoatmeal.

The present invention will be explained further in detail by means ofthe following examples, comparative examples and test examples, and thepresent invention is by no means limited to these examples and the like.

EXAMPLES Example 1 Preparation of Emulsifying Agent-Coated Iron SaltComposition (1)

An iron solution was prepared by dissolving 130 g of ferric chloridehexahydrate and 3 g of enzymatically decomposed lecithin (SUNLECITHIN L:manufactured by Taiyo Kagaku Co., Ltd.) in 600 g of ion-exchanged water.Also, 200 g of tetrasodium pyrophosphate decahydrate and 17 g ofpentaglycerol monomyristate (SUNSOFT A-141E: manufactured by TaiyoKagaku Co., Ltd.) were dissolved in 5 kg of ion-exchanged water, toprepare a pyrophosphoric acid solution. Next, the above-mentioned ironsolution was gradually added to the pyrophosphoric acid solution withstirring, and the pH of the mixture was adjusted to 3.0. Thesalt-formation of ferric pyrophosphate due to neutralization wasterminated, and thereafter the mixture was subjected to a liquid-solidseparation by centrifugation (3000G, 5 minutes), to give an emulsifyingagent-coated iron salt composition A in a solid phase portion.Subsequently, the resulting composition was dispersed by adding 800 mlof ion-exchanged water, to give 860 ml of a solution of an emulsifyingagent-coated iron salt composition A.

The average particle size of this composition as determined by laserdiffraction particle size distribution was 0.2 μm, and the iron contentwas 1.2% by weight.

Example 2 Preparation of Emulsifying Agent-Coated Iron Salt Composition(2)

Thirty grams of ferrous fumarate powder, 3 g of enzymatically decomposedlecithin (SUNLECITHIN L: manufactured by Taiyo Kagaku Co., Ltd.), and 17g of pentaglycerol trioleate (SUNSOFT A-173E: manufactured by TaiyoKagaku Co., Ltd.) were mixed, and pulverized with Cobol Mill(manufactured by Shinko Pantec Co., Ltd.), to give an emulsifyingagent-coated iron salt composition B. The resulting composition was thendispersed by adding 800 ml of ion-exchanged water, to give 810 ml of asolution of an emulsifying agent-coated iron salt composition B.

The average particle size of this composition as determined by laserdiffraction particle size distribution was 0.8 μm, and iron content was1.2% by weight.

Example 3 Preparation of Dispersion of Iron Salt and Vitamins (1)

Two grams of potassium iodide, 30 g of vitamin B₁ hydrochloride, 266 gof niacin, 28 mg of vitamin B₁₂, and 3 g of folic acid were mixed, toprepare a vitamin premix.

One-hundred grams of vitamin A palmitate (1,000,000 units/g) and 20 g ofa polyglycerol fatty acid ester (SUNSOFT AZ18G: manufactured by TaiyoKagaku Co., Ltd.) were dissolved in 280 ml of deionized water, toprepare a vitamin A emulsion with a homomixer.

To 167 ml of the solution of an emulsifying agent-coated iron saltcomposition A obtained in Example 1 were added 6.58 g of theabove-mentioned vitamin premix and 16 ml of the vitamin A emulsion, andthe mixture was stirred, to give a dispersion C of an iron salt andvitamins.

Example 4 Preparation of Dispersion of Iron Salt and Vitamins (2)

The same procedures as in Example 3 were carried out except that 167 mlof the solution of an emulsifying agent-coated iron salt composition Bobtained in Example 2 was used as an emulsifying agent-coated iron saltcomposition, to give a dispersion D of an iron salt and vitamins.

Example 5 Preparation of Iron Salt- and Vitamin-Coated Rice (1)

The amount 1.0 kg of polished rice was placed in a coating pan, and anentire amount of the dispersion C of an iron salt and vitamins preparedin Example 3 was sprayed thereto at a rate of 5 ml/minute, whilerotating the coating pan, and blowing hot air thereinto, to coat thepolished rice. Hot air was continued to be blown for dryness even afterthe termination of spraying of the dispersion. A portion having finesizes was removed with an 8-mesh sieve, to give 1.0 kg of iron salt- andvitamin-coated rice E having a water content of 10%.

Example 6 Preparation of Iron Salt- and Vitamin-Coated Rice (2)

The amount 1.0 kg of polished rice and an entire amount of thedispersion C of an iron salt and vitamins prepared in Example 3 wereplaced in a coating pan, and the polished rice was macerated at aninitial temperature of 35° C. for 1 hour with rotating the coating pan.Next, the polished rice was steam-boiled with a vapor at about 100° C.for 2 minutes, and thereafter dried with a vapor at about 70° C. Aportion having fine sizes was removed with an 8-mesh sieve, to give 1.0kg of iron salt- and vitamin-coated rice F having a water content of10%.

Example 7 Preparation of Iron Salt- and Vitamin-Coated Rice (3)

The same procedures as in Example 5 were carried out except that thedispersion D of an iron salt and vitamins obtained in Example 4 was usedas the dispersion of an iron salt and vitamins, to give 1.0 kg of ironsalt- and vitamin-coated rice G having a water content of 10%.

Furthermore, the same procedures as in Example 6 were carried out exceptthat the dispersion D of an iron salt and vitamins obtained in Example 4was used as a dispersion of an iron salt and vitamins, to give 1.0 kg ofiron salt- and vitamin-coated rice H having a water content of 10%.

Example 8 Preparation of Iron- and Vitamin-Enriched Rice (1)

Nineteen grams of cottonseed hydrogenated oil, 1 g of hexaglyceroloctastearate (SUNFAT PS68: manufactured by Taiyo Kagaku Co., Ltd.) and0.5 g of hexaglycerol condensed ricinoleate (SUNSOFT 818H: manufacturedby Taiyo Kagaku Co., Ltd.) were dissolved and mixed at 80° C. for 10minutes, to prepare a fat or oil for coating.

Next, 500 g of the iron salt- and vitamin-coated rice E obtained inExample 5 was placed in a coating pan. While rotating the coating pan, awind of a usual temperature was blown, and the above-mentioned fat oroil for coating was sprayed at a rate of 2.5 g/minute, while keeping thetemperature of the above-mentioned fat or oil for coating at 60° C., togive 520 g of enriched rice I of the present invention.

Example 9 Preparation of Iron- and Vitamin-Enriched Rice (2)

The same procedures as in Example 8 were carried out except that theiron salt- and vitamin-coated rice F, G or H obtained in Examples 6 and7 was used as the iron salt- and vitamin-coated rice, to give 520 g eachof enriched rice J, K or L of the present invention.

Comparative Example 1 Preparation of Comparative Product withEmulsifying Agent-Uncoated Iron Salt (1)

As an iron salt, 10 g of emulsifying agent-uncoated ferric pyrophosphatewas weighed so as to have the same amount in terms of an iron content,and dispersed in 160 ml of deionized water. To this dispersion wereadded 6.58 g of the vitamin premix and 16 ml of the vitamin A emulsionobtained in Example 3, and the mixture was stirred, to prepare adispersion of an iron salt and vitamins.

The same procedures as in Example 5 were carried out except that theabove-mentioned dispersion was used as a dispersion of an iron salt andvitamins, to give iron salt- and vitamin-coated rice having a watercontent of 10%. Furthermore, the same procedures as in Example 8 werecarried out, to give 520 g of comparative product iron salt- andvitamin-enriched rice M.

Comparative Example 2 Preparation of Comparative Product withEmulsifying Agent-Uncoated Iron Salt (2)

As an iron salt, 20 g of emulsifying agent-uncoated ferrous sodiumcitrate was weighed so as to have the same amount in terms of an ironcontent, and dispersed in 160 ml of deionized water. Thereto were added6.58 g of the vitamin premix and 16 ml of the vitamin A emulsionobtained in Example 3, and the mixture was stirred, to prepare adispersion of an iron salt and vitamins.

The same procedures as in Comparative Example 1 were carried out exceptthat the above-mentioned dispersion was used as a dispersion of an ironsalt and vitamins, to give 520 g of comparative product iron salt- andvitamin-enriched rice N.

Comparative Example 3 Preparation of Comparative Product Coated with Fator Oil without Containing Polyglycerol Fatty Acid Ester

Nineteen grams of cottonseed hydrogenated oil and 1 g of rice bran waxwere dissolved and mixed at 80° C. for 10 minutes, to prepare a fat oroil for coating.

Next, the same procedures as in Example 8 were carried out, except that500 g of the iron salt- and vitamin-coated rice E obtained in Example 5was used, and that the above-mentioned fat or oil was used as a fat oroil for spray-coating, to give 520 g of comparative product iron salt-and vitamin-enriched rice O was obtained.

Test Example 1 Run-Off Test of Iron and Vitamins Upon Washing Rice

One gram of each kind of iron- and vitamin-enriched rice 1 to 0 of theinventive products and comparative products was respectively mixed with200 g of polished rice, to give test sample rice. The procedures ofadding 250 ml of tap water to each of test sample rice, washing the testsample rice with water so as to rub and loosen at a rate of about 30rotations per minute, and draining water therefrom were repeated fourtimes. The drained water was collected, and the amounts of iron andvitamins contained in the drained water were determined. The percentloss was obtained by calculating a ratio of the content to that in 1 gof the enriched rice. The results are summarized in Table 1. Here, theamounts of iron and vitamins were determined according to the basis ofStandard Methods of Analysis for Hygiene Chemists. TABLE 1 Enriched RiceUsed for Test Percent Loss (%) by Washing Rice Sample Rice Iron VitaminB₁ Vitamin A Folic Acid Inventive 3.9 3.1 4 3.8 Product I Inventive 4.54.3 5.2 4.8 Product J Inventive 8.3 9.1 8.5 9.2 Product K Inventive 10.110.3 9.8 10.3 Product L Comparative 15.8 16.5 16.2 17.1 Product MComparative 20.9 20.8 19.8 20.5 Product N Comparative 40.5 41.5 40.142.1 Product O

It is clear from above results that the inventive products had smallerloss of iron and vitamins by washing rice than the comparative products,and that ferrous fumarate had smaller loss of iron and vitamins lessthan ferric pyrophosphate.

Test Example 2 Test for Residual Vitamins upon Storage

The inventive product I and comparative products M and N were stored atroom temperature for one month, and thereafter the amounts of vitamin B₁and folic acid were determined. The residual ratio was obtained bycalculating a ratio of the amount to that before storage. The resultsare summarized in Table 2. TABLE 2 Enriched Rice Residual Ratio (%)after One-Month Used for Storage at Room Temperature Sample Vitamin B₁Folic Acid Inventive 83.5 96.2 Product I Comparative 45.8 53.2 Product MComparative 35.9 47.4 Product N

It is clear from above results that the case where the inventiveproduct, namely the emulsifying agent-coated iron salt composition wasused had higher stability than the cases where an emulsifyingagent-uncoated iron salt was used.

Also, in external appearance, the inventive product showed no change incolor tone, while both the comparative products were colored brown.

Test Example 3 Run-Off Test of Iron by Washing Enriched Rice Coated withFat or Oil Having Varying Amounts of Polyglycerol Fatty Acid Ester

Each kind of test samples was prepared by varying the amounts ofhexaglycerol octastearate and hexaglycerol condensed ricinoleate inExample 8. Each test sample was subjected to the same rice washing testas in Test Example 1, and the percent loss was obtained. The results aresummarized in Table 3. TABLE 3 Amount of Ratio of Polyglycerol Amount ofHexaglycerol Fatty Acid Ester Based Hexaglycerol Condensed Percent Loss(%) on 100 parts by weight Octastearate Ricinoleate by Washing Rice ofHydrogenated Oil 0 g 0 g 20.5 0 3 g 1 g 6.5 21.1 1 g 1 g 4.5 10.5 1 g0.5 g 3.9 7.9 1.5 g 0 g 8.3 7.9

It is clear from the table that one without any addition of apolyglycerol fatty acid ester had a larger run-off of iron by washingrice, and that the combined use of hexaglycerol octastearate withhexaglycerol condensed ricinoleate had a larger run-off of iron thanthat of hexaglycerol octastearate alone, even though a total amount ofthe polyglycerol fatty acid ester was large.

Example 10 Preparation of Enriched Barley

The same procedures as in Example 5 were carried out except that 1.0 kgof barley was used in place of polished rice, to give iron salt- andvitamin-coated barley having a water content of 10%. Further, the sameprocedures as in Example 8 were carried out, to give 520 g of enrichedbarley of the present invention.

Test Example 4 Confirmation of Flavor During Rice Cooking

One gram of each enriched rice of the present invention obtained inExample 8 and the enriched barley obtained in Example 10 wasrespectively mixed with 200 g of polished rice, to give test samplerice. Each of test sample rice was washed in the same manner as in TestExample 1, and thereafter iron- and vitamin-enriched rice was boiledwith electric rice cooker. Those with addition of the same amount ofrice or barley without enrichment with iron and vitamins were preparedas comparative products. Sensory test was conducted. As a result, therewas no difference in flavor therebetween.

Example 11 Preparation of Mixture Containing Iron Salt, Hydrogenated Oiland Polyglycerol Fatty Acid Ester (1)

Thirty grams of ferric pyrophosphate, 8 g of hexaglycerol condensedricinoleate (SUNSOFT 818H; HLB=1: manufactured by Taiyo Kagaku Co.,Ltd.), and 62 g of palm hydrogenated oil (melting point: 36° C.) weremixed, and the mixture was pulverized and homogeneously mixed with CobolMill (manufactured by Shinko Pantec Co., Ltd.), to give 96 g of amixture P.

The average particle size of the iron salt as determined by laserdiffraction particle size distribution was 0.4 μm.

Example 12 Preparation of Mixture Containing Iron Salt, Hydrogenated Oiland Polyglycerol Fatty Acid Ester (2)

Thirty grams of ferrous sulfate heptahydrate, 8 g of hexaglycerolcondensed ricinoleate (SUNSOFT 818H; HLB=1: manufactured by Taiyo KagakuCo., Ltd.), and 62 g of palm hydrogenated oil (melting point: 36° C.)were mixed, and the mixture was pulverized and homogeneously mixed withCobol Mill (manufactured by Shinko Pantec Co., Ltd.), to give 96 g of amixture Q.

The average particle size of the iron salt as determined by laserdiffraction particle size distribution was 0.4 μm.

Example 13 Preparation of Mixture Containing Iron Salt, Hydrogenated Oiland Polyglycerol Fatty Acid Ester (3)

Thirty grams of ferric pyrophosphate, 8 g of hexaglycerol condensedricinoleate (SUNSOFT 818H; HLB=1: manufactured by Taiyo Kagaku Co.,Ltd.), and 62 g of palm hydrogenated oil (melting point: 36° C.) werehomogeneously mixed with a homomixer, to give 94 g of a mixture R.

The average particle size of the iron salt as determined by laserdiffraction particle size distribution was 3.5 μm.

Example 14 Preparation of Mixture Containing Iron Salt, Hydrogenated Oiland Polyglycerol Fatty Acid Ester (4)

Twenty grams of ferric pyrophosphate, 7 g of hexaglycerol condensedricinoleate (SUNSOFT 818H; HLB=1: manufactured by Taiyo Kagaku Co.,Ltd.), 1 g of enzymatically decomposed lecithin (SUNLECITHIN A:manufactured by Taiyo Kagaku Co., Ltd.), 54.2 g of palm hydrogenated oil(melting point: 36° C.), 15 g of the vitamin premix of Example 3, 2.5 gof vitamin A palmitate (1,000,000 units/g), and 0.3 g of casein calciumpeptide (CCP: manufactured by Taiyo Kagaku Co., Ltd) were mixed, and themixture was pulverized and homogeneously mixed with DYNO-MILL(manufactured by Shinmaru Enterprises Corporation), to give 96 g of amixture S.

The average particle size of the solid content containing the iron saltin the mixture as determined by laser diffraction particle sizedistribution was 0.3 μm.

Example 15 Preparation of Mixture Containing Emulsifying Agent-CoatedIron Salt Composition, Vitamins, Hydrogenated Oil and Polyglycerol FattyAcid Ester (1)

Ten grams of dextrin was dissolved in 860 ml of the solution of anemulsifying agent-coated iron salt composition A prepared in Example 1,and the solution was spray-dried, to give 90 g of a powder of anemulsifying agent-coated iron salt composition.

The amount 46.5 g of the above-mentioned powder of an emulsifyingagent-coated iron salt composition, 6 g of hexaglycerol condensedricinoleate (SUNSOFT 818H; HLB=1: manufactured by Taiyo Kagaku Co.,Ltd.), 0.8 g of enzymatically decomposed lecithin (SUNLECITHIN A:manufactured by Taiyo Kagaku Co., Ltd.), 54.2 g of palm hydrogenated oil(melting point: 36° C.), 15 g of the vitamin premix of Example 3, and2.5 g of vitamin A palmitate (1,000,000 units/g) were mixed, and themixture was pulverized and homogeneously mixed with DYNO-MILL(manufactured by Shinmaru Enterprises Corporation), to give 126 g of amixture T.

The average particle size of the solid content containing the iron saltin the mixture as determined by laser diffraction particle sizedistribution was 0.3 μm.

Example 16 Preparation of Iron-Enriched Rice (1)

Six-hundred grams of polished rice was placed in a coating pan, andcoated by spraying 20.6 g of the mixture P obtained in Example 11 to thepolished rice at a rate of 2.5 g/minute while rotating the coating pan,blowing wind of an ordinary temperature, and keeping the temperature at60° C., to give 620 g of enriched rice U of the present invention.

Example 17 Preparation of Iron-Enriched Rice (2)

The same procedures as in Example 16 were carried out except that 31 gof the mixture Q obtained in Example 12 was sprayed as a coating liquid,to give 630 g of enriched rice V of the present invention.

Example 18 Preparation of Iron-Enriched Rice (3)

The same procedures as in Example 16 were carried out except that 20.6 gof the mixture R obtained in Example 13 was sprayed as a coating liquid,to give 620 g of enriched rice W of the present invention.

Example 19 Preparation of Iron-Enriched Rice (4)

The same procedures as in Example 16 were carried out except that 31 gof the mixture S obtained in Example 14 was sprayed as a coating liquid,to give 630 g of enriched rice X of the present invention.

Example 20 Preparation of Iron-Enriched Rice (5)

The same procedures as in Example 16 were carried out except that 38 gof the mixture T obtained in Example 15 was sprayed as a coating liquid,to give 635 g of enriched rice Y of the present invention.

Comparative Example 4 Preparation of Rice Coated in Two-Step with IronSalt-Oil

Six-hundred grams of polished rice was placed in a coating pan, andcoated by spraying a dispersion prepared by dispersing 6.2 g of ferricpyrophosphate in 200 ml of deionized water at a rate of 5 ml/minute,while rotating the coating pan and blowing hot air therein. Even afterfinishing spraying the liquid, the hot air was continued to be suppliedto dry the rice so as to have a water content of 10%. Thereafter, theair supplied was changed to cool air to cool the rice to 30° C. Next,the air supplied was then changed to an ordinary temperature, and 13.8 gof palm hydrogenated oil (melting point: 36° C.) was sprayed at a rateof 2.5 g/minute, while keeping at a temperature of 60° C., to coat therice, to give 620 g of a comparative product iron-enriched rice Z.

Test Example 5 Run-off Test of Iron by Washing Rice

One gram of each kind of enriched rice U to Z prepared as the inventiveproducts and the comparative products was respectively mixed with 200 gof polished rice, to give test sample rice. The procedures of adding 250ml of tap water to each of test sample rice, washing the test samplerice with water so as to rub and loosen at a rate of about 30 rotationsper minute, and draining water therefrom were repeated four times. Thedrained water was collected, and the amount of iron contained in thedrained water was determined by atomic absorption photometry. Thepercent loss was obtained by calculating a ratio of the content to thatin 1 g of enriched rice. The results are summarized in Table 4. TABLE 4Percent Loss of Iron Enriched Rice used for by Washing Rice Test SampleRice (%) Inventive Product U 3.1 Inventive Product V 9.5 InventiveProduct W 10.3 Inventive Product X 3.8 Inventive Product Y 4.2Comparative Product Z 27.5

It is clear from above results that the inventive products had smallerloss of iron by washing rice than that of the comparative product.Moreover, insoluble ferric pyrophosphate had smaller loss than that ofwater-soluble ferrous sulfate, and even when the same ferrouspyrophosphate was used, one that was pulverized had smaller loss thanone that was unpulverized.

Example 21 Preparation of Enriched Barley

The same procedures as in Example 16 were carried out except that 600 gof rice grain barley was used in place of the polished rice, to give 620g of enriched barley of the present invention.

Test Example 6 Confirmation of Flavor During Rice Cooking

Each of 1 g of the enriched rice of the present invention obtained inExample 16 and the enriched barley of the present invention obtained inExample 21 was respectively mixed with 200 g of polished rice, to givetest sample rice. Each of the test sample rice was washed in the samemanner as in Test Example 5, and thereafter rice enriched with iron wasboiled with an electric rice cooker. The same amount of rice or barleywithout enrichment with iron was added to polished rice, to givecomparative products. Sensory test was conducted. As a result, there wasno difference in flavor therebetween.

INDUSTRIAL APPLICABILITY

According to the present invention, enriched rice and the like havingvery small run-off loss of the enrichment nutrients during washing withwater than those of conventional enriched rice and enriched barley canbe easily and efficiently provided. Since the flavor of the cooked ricemixed with the enriched rice is not substantially lowered, the enrichedrice and the like are very useful for those individuals who take riceand the like as principal foods, so that their industrial applicablevalues are significant.

1. Iron- and vitamin-enriched rice or barley, characterized in that ricegrains or barley grains are coated with an emulsifying agent-coated ironsalt composition and vitamins, and further coated with a mixture of ahydrogenated oil and a polyglycerol fatty acid ester.
 2. Iron-enrichedrice or barley, characterized in that rice grains or barley grains arecoated with a mixture comprising an iron salt, a hydrogenated oil and apolyglycerol fatty acid ester.
 3. Iron- and vitamin-enriched rice orbarley, characterized in that rice grains or barley grains are coatedwith a mixture comprising an emulsifying agent-coated iron saltcomposition, vitamins, a hydrogenated oil and a polyglycerol fatty acidester.
 4. The enriched rice or barley according to any one of claims 1to 3, characterized in that the iron salt has an average particlediameter of 2 μm or less.